The S&P options project was entirely experimental, Goh told CoinDesk -- the challenge was mainly to see if it could be done. (The publicity probably doesn't hurt, either.) Since the trade would essentially be automated via computer programming, it would be less expensive to conduct and settle a lot faster, maybe in just 10 or 15 minutes, according to Goh.

Goh said the technology that made it possible comes from Crypto Garage, a subsidiary of the publicly traded, Tokyo-based tech firm Digital Garage. Crypto Garage has developed an expertise in smart contracts, small strings of programming that can be encoded into the bitcoin blockchain to run when activated.

The transaction needed to cross on the bitcoin blockchain, Goh said, because it's the most secure in the industry, even though smart contracts are generally considered easier to program on the ethereum network.

... In theory, he says, the cost would have remained the same even if the notional amount of the trade had stretched into the millions or billions of dollars.